Vibratory conveying systems are known in the art. A vibratory drive is connected directly to the conveying frame or bed in most conventional vibratory conveying systems. Some experimentation has been conducted wherein the vibratory device is connected to a support frame and the support frame is excited or primarily vibrated with the vibration being transferred through springs indirectly to the conveying member or bed. Exemplary conventional systems are described in U.S. Pat. Nos. 2,876,891, 2,951,581 and 3,380,572.
Newer designs have provided a system wherein the vibration amplitude of the excited frame is reduced while the conveyor bed or member is vibrated at its natural frequency of maximum amplitude. The principal variables are the rpm of the vibratory drive member, the spring constant of the support springs supporting the conveyor bed on the excited frame, the weight of the conveyor bed, the weight of the product or load being conveyed and the weight of the excited frame.
The generally recognized advantages of such systems over conventional direct vibratory conveyors are that it is possible under some conditions to transfer less vibration into the floor or ceiling supports and to provide a conveyor that is considerably less massive than direct drive vibrating systems.
U.S. Pat. No. 4,313,535 teaches an improved excited frame, vibratory conveying apparatus for moving particulate material. Plural supports or springs space a conveyor member from the excited frame. The device of the '535 patent teaches a vibratory drive means mounted to an elongated conveying frame for vibrating the elongated conveying frame in an intended direction for conveying particulate material.
The drive means produces a vibratory motion along a linear line of force. The device of the '535 patent provides a configuration for operation over a large range of loads without any appreciable vibration of the excited frame.
Such systems are preferably configured for use with various types of particulate material. For example, one conveying apparatus can be configured to convey one type of material in one application and another similar conveying apparatus can be configured to convey another material in another application.
Vibratory conveying apparatuses are preferably tuned for a particular application. In some applications, vibratory conveying apparatuses have been observed to go out of tune over a period of time of use. For example, a vibratory conveying apparatus can go out of tune if too much particulate material is provided upon the bed.
Operating the vibratory conveying apparatuses in an out-of-tune state can have detrimental effects upon the apparatuses themselves. For example, such operation can lead to premature failure of the springs provided intermediate the bed and the frame.
Thus, there exists a need to provide improved conveying apparatuses and methodologies which overcome the problems associated with the prior art.